Catheters have many uses in modern medicine. One reason for their importance is their ability to guide and support additional instruments during a procedure at an anatomic location. In the procedure, a guide catheter is inserted between an entry site and advanced as far as is safe towards, for example, a lesion or a region of interest. Current catheters have smooth exteriors, nonetheless, the catheters can be held in place through friction with the walls in which the catheter is placed. As most anatomical conduits are not straight, friction provided to prevent movement of the catheter during a procedure occurs and increases with each bend that the catheter traverses. As one bend is traversed, one side of a vessel wall provides a friction point and as a second bend is thereafter traversed, a different side of the vessel wall provides a second friction point and so on for each bend. It is self-evident that the catheter must be flexible to traverse multiple bends but it still must retain its shape in order to be extended through a tortuous path. In comparison, catheters having a distal inflatable balloon find securement in an anatomical site by inflating the balloon to anchor between/within opposing walls, such as in a blood vessel. But, when so anchored, the catheter cannot move longitudinally without causing damage to the inflation site. Balloon catheters are problematic due to their total occlusion of blood flow in a given vessel during use and for the stress they place on vessel walls, but they are also unusable if the procedure requires multiple sets of extensions into anatomy and securement therein for each step.
Guide catheters are used as passageways to advance additional devices, such as smaller catheters or interventional devices such as stentrievers or embolic coils. Guide catheters simplify positioning of these smaller devices, allowing them to be easily advanced to the lesion or region of interest. Designers of current guide catheters face a trade-off between navigability and staying power. A more flexible catheter can be advanced through more complex anatomies, and can potentially be advanced closer to a lesion or region of interest. However, a more flexible catheter exerts less normal force on vessel walls for a given deformation of the catheter and, as such, is easier to back out from the region of interest due to lessened friction. Accordingly, it is not possible currently to improve navigability without worsening staying power and equally not possible to improve staying power without worsening navigability. It would, therefore, be desirable to overcome this and provide improvement in both staying power and navigability.
A significant issue encountered with guide catheters is “back-out”, wherein pushing force applied to a catheter or implement within the guide catheter causes the guide catheter to move within the vasculature relative to its initial position. Because of the strain energy stored in a deformed guide catheter, these “back-outs” can be very sudden and dramatic events. Back-outs have adverse consequences with regard to patient safety and doctor success. When a guide catheter dislodges, it often brings with it the additional catheters or implements being used for a procedure, compromising what is often a complex set of device positions and placements through the patient's vasculature. This increases time in the operating room by necessitating re-catheterization of the patient. If a “back-out” event occurs during a critical moment in a procedure, for example, with deployment of a flow diverter, back-out can damage a device costing $10,000 or more and potentially cause severe harm to the patient. Accordingly, it would be desirable to provide a catheter that resists “back-out” and provides a reliable, stable guide.
The issues of support and back out are relevant in many fields, including interventional neurology and cardiology.
Another issue of relevance to catheters and catheter-based device users is ease of operation. Catheter operators desire a 1-to-1 operation—that is to say, a configuration that allows manipulations of a catheter's proximal shaft or hub to translate directly, consistently, and predictably to motion of the catheter's distal end, which includes both prismatic (insertion/retraction) motions and rotational motions. 1-to-1 operation cannot be perfectly ideal, in other words, with current materials, 1-to-1 operation is approximately or substantially 1-to-1 operation. Therefore, as used herein, the phrase 1-to-1 operation is defined to include a variance that one skilled in the art would know to be a reasonable tolerance. Guide catheters also help provide 1-to-1 operation to additional or secondary catheters and devices that do not have such distal end mobility. Devices constrained within the guide catheter's relatively stiff and smooth inner lumen are not able to buckle or push into compliant vessel walls. As such, guide catheters increase an operator's consistency, precision, and ultimately safety. It would be beneficial to provide a catheter that increases flexibility, increases retention force, and still provides 1-to-1 operation.
Thus, a need exists to overcome the problems with the prior art systems, designs, and processes as discussed above.